English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Context: KELT-9 b exemplifies a newly emerging class of short-period gaseousexoplanets that tend to orbit hot, early type stars - termed ultra-hotJupiters. The severe stellar irradiation heats their atmospheres totemperatures of $\sim 4,000$ K, similar to the photospheres of dwarf stars. Dueto the absence of aerosols and complex molecular chemistry at suchtemperatures, these planets offer the potential of detailed chemicalcharacterisation through transit and day-side spectroscopy. Studies of theirchemical inventories may provide crucial constraints on their formation processand evolution history.  Aims: To search the optical transmission spectrum of KELT-9 b for absorptionlines by metals using the cross-correlation technique.  Methods: We analyse 2 transits observed with the HARPS-N spectrograph. We usean isothermal equilibrium chemistry model to predict the transmission spectrumfor each of the neutral and singly-ionized atoms with atomic numbers between 3and 78. Of these, we identify the elements that are expected to have spectrallines in the visible wavelength range and use those as cross-correlationtemplates.  Results: We detect absorption of Na I, Cr II, Sc II and Y II, and confirmprevious detections of Mg I, Fe I, Fe II and Ti II. In addition, we findevidence of Ca I, Cr I, Co I, and Sr II that will require further observationsto verify. The detected absorption lines are significantly deeper than modelpredictions, suggesting that material is transported to higher altitudes wherethe density is enhanced compared to a hydrostatic profile. There appears to beno significant blue-shift of the absorption spectrum due to a net day-to-nightside wind. In particular, the strong Fe II feature is shifted by $0.18 \pm0.27$ km~s$^{-1}$, consistent with zero. Using the orbital velocity of theplanet we revise the steller and planetary masses and radii.

A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b